Gasoline containing antioxidants



United States Patent GASOLINE CONTAINING AN TIOXIDANTS Clyde S. Scanley and Ken Matsuda, Stamford, Conn., and Ralph A. Coleman, Middlesex, N.J., assignors to American Cyanamid Company, New York, N.Y., a corporation of Maine No Drawing. Filed Dec. '3, 1957, Ser. No. 700,301

3 Claims. (CI. 44-63) This invention relates to hydrocarbon fuels stabilized against oxidative deterioration by a novel class of antioxidants.

It is well known that volatile hydrocarbon fuels of the type of cracked gasoline tend to deteriorate upon storage, and that this deterioration is due to polymerization and gum formation initiated by the presence of oxygen. It is a principal object of our present invention to provide a novel class of antioxidants which, when incorporated into the gasoline in small but effective amounts, will delay or inhibit such oxidative deterioration, thus increasing the storage stability of the fuel.

The oxidation inhibitors of this class present the im-.

portant advantage over other known inhibitor that they can be prepared from relatively cheap and easily obtainable raw materials and are therefore available at a relatively low cost.

Our invention is based on the discovery that the condensation products of cyanogen with primary aliphatic diamines are effective gasoline antioxidants.

When cyanogen is condensed with an alkylenediamine ammonia is evolved and bicyclic compounds are obtained having the formula:

Na Na in which n represents the number of carbon atoms in the alkylenediamine used. We have found that these cyclic compounds are effective gasoline antioxidants. Compounds of the same general class can also be prepared by condensing cyanogen with polyalkylenepolyamines such as ethylenediamine, diethylenetriamine, 3,3-iminobispropylamine, 1,2-propanediamine, 1,3-propanecliamine, triethylenetetramine, 1,4-butanediarnine and the like.

The compounds of the above types are light colored solids that are soluble in gasoline and other cracked hydrocarbon distillates in the amounts required to impart eifective antioxidant action. The exact amounts to be used will of course vary with the type of gasoline or other hydrocarbon distillate and with the degree of protection desired; in most cases quantities within the range of about 0.001% to 0.1% are suiiicient. These quantities are hereinafter designated as antioxidizing amounts. Our novel antioxidants may be used alone, or in admixture with each other.

The invention will be further described and illustrated by the following examples.

Example 1 2,2-bi-2-irnidazoline of the formula CH2--N\ N-CH2 CG CHPNII/ NH-om is prepared from ethylenediamine and cyanogen by the method of Woodburn and OGee, J. Org. Chem. 17, 123544 (1952).

2,970,897 Patented Feb. 7, 1961 Example 3 2,2'-bis-(4,5,6,7-tetrahydro-1,3-diazepine) of the formula OH;OH -N CH2CH2NH is prepared by introducing 26 parts of cyanogen into a solution of 88 parts of 1,4-butanediamine in 236 parts by weight of absolute ethanol at 7 C. dudring 20 minutes, stirring for one hour at 3 C. and then heating under reflux (81.5 C.) for about 100 hours while introducing a stream of nitrogen gas to facilitate ammonia removal. The alcohol is then distilled oil, water is added and the aqueous solution is extracted six times with ether. The extract is dried and decolorized with active charcoal and the ether evaporated leaving the desired product, a cream-colored solid melting at 83- 90 C. This method is described in further detail by Ken Matsuda in U. S. application Serial No. 652,672 filed April 15, 1957, now US. Patent No. 2,819,262.

Example 4 The compounds of the preceding examples were tested as antioxidants in cracked gasoline by the A.S.T.M.D- 525-49 oxygen bomb test in which a 50 ml. sample of gasoline containing the antioxidant is maintained under p.s.i. oxygen pressure at about 90-100 C. until the break point is reached, and the induction period is measured. The results are shown in the following table in which the induction time ratio is calculated by the formula:

Induction period for gasoline additive What we claim is:

1. Gasoline subject to oxidative deterioration and containing, in an ant.oxidizing amount, a compound of the formula (CE2) CC\ /OH2)..

NE NH in which Pi is a whole number from 2 to 4 inclusive.

2. Gasoline subject to oxidative deterioration and con taining, in an antioxidizing amount, a compound of the formula 3 3. Gasoline subject to oxidative deterioration and containing, in an antioxidizing amount, a compound of the formula References Cited in the file of this patent UNITED STATES PATENTS Clarkson Mar. 5, 1946 Biswell May 8, 1951 Caron et a1 May 15, 1951 Gleim May 29, 1956 Chenicek July 10, 1956 Cyba et a1 July 22, 1958 UNITED STATES PATENT OFFICE CERTIFICATION OF CORRECTION P t t N 2,970,897 February 7, 1961 Clyde S. Scanley et al.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

and column 2, lines 61 to Column 1, lines 38 to 41,

should appear as shown 64, the formula, each occurrence, below instead of as in the patent:

column 2, lines 3 to 7, and column 3, lines 5 to 8, the formula, each occurrence, should appear as shown below instead of as in the patent:

Signed and sealed this 3rd day of April 1962.

(SEAL) Attest:

ERNEST W. SWIDER Attesting Officer DAVID L LADD Commissioner of Patents 

1. GASOLINE SUBJECT TO OXIDATIVE DETERIORATION AND CONTAINING, IN AN ANTIOXIDIZING AMOUNT, A COMPOUND OF THE FORMULA 